1. Field of the Invention
The present invention relates generally to household refrigerators and, more particularly, to a base pan of a refrigerator for an evaporation of water formed from melted ice and frost.
2. Description of the Prior Art
Generally, refrigerators are used to store foodstuffs at the lower temperature in order to maintain freshness of the foodstuffs. They generally include a compressor which compresses and circulates a liquid-phase refrigerant, an evaporator which causes a pressure drop of the liquid-phase refrigerant so that the refrigerant is evaporated, thereby generating a chilled air, a condenser which condenses the vapor-phase refrigerant, thereby changing the vapor-phase refrigerant into liquid-phase refrigerant, and circulates the liquid-phase refrigerant to the compressor. The chilled air generated by the evaporator is introduced into a compartment by a fan.
Present day household refrigerators usually include in its lower portion an uninsulated space in which a compressor and a condenser are housed together with a drip pan. A drain tube is usually provided to discharge melted frost water into the pan where it receives heat from the condenser and the compressor unit in an amount sufficient to cause evaporation of the water collected in the pan at rates sufficient to keep the pan from overflowing.
In some cases, such as disclosed in U.S. Pat. No. 4,023,380, there is provided an improved molded plastic evaporation pan for collecting and evaporating the defrost water of a household refrigerator. Referring more particularly to FIGS. 1 and 2, the evaporation pan 10 is housed in the uninsulated lower compartment 12 of a refrigerator 14. This compartment is defined by sidewalls 16 and 18, rear wall 20, base 22, and by the upper dividing wall 24 adjacent the fresh food compartment (not shown) of the refrigerator. Together with the evaporation pan 10, a compressor 26 is housed in compartment 12. The defrosting components (not shown) of the refrigerator unit 14 accomplish periodic defrosting resulting in melted ice and frost which must be discharged to the evaporation pan. This discharging is achieved by means of a drain tube 28 made of flexible material directing the defrost water to the evaporation pan 10.
The pan 10 is formed from a single sheet of plastic material and has a bottom wall 30 and an upstanding continuous peripheral wall 32 forming front, rear and side walls. The bottom wall 30 includes a centrally located recessed portion 34 of circular configuration. Disposed adjacent the recessed portion 34 are four mounting posts 37 which are integrally formed with the bottom wall 30 of the pan. The portion of bottom wall 30 adjacent the mounting posts is thicker somewhat to provide reinforcement as shown in FIG. 2. A series of annular lugs 40 are inserted over the vertical posts. The outside wall of each annular lugs 40 is shaped with a groove 46 to receive a portion of supporting plate 48 on which is mounted the compressor 26. The evaporation pan 10 is fixedly mounted to the base 22 of the refrigerator and includes one or more wells 54 which serve to receive the defrost water discharged through the drain tube 28.
However, the conventional evaporation pan as above described has disadvantages in that the water collected in the pan does not makes contact with the heat radiating component such as the compressor and condenser, and the supporting plate is interposed on a heat transfer path, so an evaporating efficiency thereof decreases and a steam generated from the evaporation of the defrost water dispersed in the lower compartment may lead to rusting of the components installed therein.